[BUG] Normalizers always tranform input to lowercase

[umoqnier]

Describe the bug
Normalizers always tranform input to lowercase and information can be missing for other NLP tasks

To Reproduce

Steps to reproduce the behavior:

from elotl.otomi.orthography import Normalizer
N = Normalizer("ots")
input_str = "Ra ngaho ra tso̱ y'o̱te:"
print(N.normalize(input_str))
>>> "ra ngajo ra tso̱ y'o̱te:"

Expected behavior

from elotl.otomi.orthography import Normalizer
N = Normalizer("ots")
input_str = "Ra ngaho ra tso̱ y'o̱te:"
print(N.normalize(input_str))
>>> "Ra ngajo ra tso̱ y'o̱te:"

Desktop (please complete the following information):

• OS: Any
• Version: 0.0.1.16